C61 may refer to: , an Admirable-class minesweeper of the Mexican Navy Bill C-61 (39th Canadian Parliament, 2nd Session), an act to amend the Copyright Act Caldwell 61, a galaxy Caudron C.61, a French civil transport biplane Fairchild C-61 Forwarder, an American military aircraft JNR Class C61, a class of Japanese steam locomotive Prostate cancer Reduction of Hours of Work (Textiles) Convention, 1937 of the International Labour Organization Ruy Lopez, a chess opening